AES E-Library

Near and Far-field Control of Focused Sound Radiation Using a Loudspeaker Array

In this paper, a sound manipulation technique is proposed to prevent unwanted eavesdropping or disturbing others in the vicinity if a multimedia device is being used in a public place. This is capable of realizing to create a spatial region having highly acoustic potential energy at the listener’s position. For doing so, the paper discusses the design of multi-channel filters with a given the spatial directivity pattern for a given arbitrary loudspeaker array configuration. Firstly some limitations in using conventional beamforming technique are presented, and then a novel control strategy is suggested for reproducing a desired acoustic property in a spatial area of interest close to the loudspeaker array. This technique also allows us to control an acoustic property in area relatively far from the array with a single objective function. In order to precisely produce a desired shape of energy distribution in both areas, spatial weighting technique is introduced. The results are compared with those from controlling each area separately.